1. Technical Field
The present methods and systems relate to communications between wireless modules and a network, and more particularly, efficient methods and systems for supporting secure, energy efficient, and bandwidth efficient communications between a wireless node and a server through a wireless network.
2. Description of Related Art
The combination of “machine-to-machine” (M2M) communications and wireless networking technology is a promising and growing field. Among many potential benefits, M2M technologies allow the remote monitoring of people, assets, or a location where manual monitoring is not economic, or costs can be significantly reduced by using automated monitoring as opposed to manual techniques. Prominent examples today include vending machines, automobiles, alarm systems, and remote sensors. Fast growing markets for M2M applications today include tracking devices for shipping containers or pallets, health applications such as the remote monitoring of a person's glucose levels or heartbeat, and monitoring of industrial equipment deployed in the field.
In addition, M2M communications can provide remote control over actuators that may be connected to a M2M device, such as turning on or off a power switch, locking or unlocking a door, or similar remote control. A decision to change or adjust an actuator associated with an M2M device can utilize one or a series of sensor measurements. As one example, if a building or room is too cold, then temperature can be reported to a central server by an M2M device and the server can instruct the M2M device to turn on a switch that activates heat or adjusts a thermostat. As the costs for computer and networking hardware continue to decline, together with the growing ease of obtaining wireless Internet access for small form-factor devices, the number of economically favorable applications for M2M communications grows.
Wireless technologies such as wireless local area networks and wireless wide area networks have proliferated around the world over the past 15 years, and usage of these wireless networks is also expected to continue to grow. Wireless local area network (LAN) technologies include WiFi and wireless wide area network (WAN) technologies include 3rd Generation Partnership Project's (3GPP) 3rd Generation (3G) Universal Mobile Telecommunications System (UMTS) and 4th Generation (4G) Long-term Evolution (LTE), LTE Advanced, and the Institute of Electrical and Electronics Engineers' (IEEE) 802.16 standard, also known as WiMax. The use of wireless technologies with “machine-to-machine” communications creates new opportunities for the deployment of M2M modules in locations without fixed-wire Internet access, but also creates a significant new class of problems that need to be solved. First, many wireless wide-area networking standards were designed and optimized for mobile phones, which may be continuously connected to the network during the day (i.e. non-sleeping hours for most subscribers while they may charge phones at night), in order to receive inbound phone calls and messages. In this case, the radio may be in an idle state but utilizing discontinuous reception, but the radio is still active and drawing power in order to receive and process incoming signaling from the network such as a Public Land Mobile Network (PLMN).
A need exists in the art for the communication between a wireless module and either a PLMN network or a monitoring server (accessed by the wireless module through the PLMN) to be highly energy and bandwidth efficient in order to conserve battery life. A limiting factor for a wireless module for M2M applications deployed or installed into the field is the lifetime of the battery of the wireless module. M2M applications have unique requirements compared to traditional mobile phones, where the data transmitted may typically be relatively small messages such as a few kilobtyes or less several times a day. The energy to simply transmit a single packet can be relatively high for M2M applications. Junxian Huang et al noted in their paper to MobiSys 2012, “Based on these observations, LTE is less energy efficient during idle state and for transferring smaller amount of data. For example, if only one packet is transferred, the energy usage considering both promotion and tail energy for LTE, 3G and WiFi is 12.76J, 7.38J, and 0.04J, respectively” (A Close Examination of Performance and Power Characteristics of 4G LTE Networks”, page 2). A need exists in the art to reduce power usage while sufficiently conforming to standards, in order to transmit data from a wireless module to a server.
If the transmission techniques for the wireless module are not energy efficient, the system will require more frequent manual intervention for the replacement or recharging of batteries. If the battery becomes sufficiently low, then communication with the wireless module will be lost, or the frequency decreased for (i) sensor measurements or reports sent by the wireless module or (ii) receive actuator commands sent by a monitoring server. A need exists in the art whereby the energy saving techniques to send data should preferably leverage the signaling methods described by established wireless WAN standards in order to properly support and interoperate with commercially deployed wireless networks. A need exists in the art to implement the signaling methods described by established and future wireless WAN standards in a manner that is more efficient for wireless modules than consumer mobile handsets.
A need exists in the art to secure communication between a wireless module and a server in an efficient manner. As wireless modules and servers supporting M2M communications increasingly leverage the public Internet, a need exists in the art to provide a high degree of security while balancing a competing need to maximize battery life of wireless modules. A need exists in the art for the security algorithms to support widely deployed public key infrastructure (PKI) processes and support software. And other needs exist in the art as well, as the list recited above is not meant to be exhaustive but rather illustrative.